Oppose & Prevent
Mainly friction.
There are many types of forces that oppose motion such as friction, drag and most universal, gravity.
Inertia is a property of matter that makes it harder to move, so that is probably what you are thinking of, but technically, forces do not oppose motion. Depending upon the direction in which a force is applied, one force can oppose another force that is acting in an opposite direction, but forces are not opposed to motion as such.
Relative motion
Relative motion
Famer are more important than doctor oppose the motion?
Friction.
Friction.
Friction or Resistance
Friction!
Balanced forces do not change its motion (no acceleration). Unbalanced forces changes the motion of the object (acceleration).